Insulting US Term for a Snitch; a Rodent Analogy

This page is the CodyCross answer for the clue below from House of Horrors, Group 1105, Puzzle 5 (Loose Floorboards).

Question is: Insulting US Term for a Snitch; a Rodent Analogy

and the answer is: RATFINK

Word Meaning:

RAT FINK — Alternative form of ratfink.

Definitions from Wiktionary.